kaposi sarcoma

What Is Kaposi sarcoma?
Kaposi sarcoma (KS) is a cancer that develops from the cells that line lymph or blood vessels. The abnormal cells of KS form purple, red, or brown blotches or tumors on the skin. These affected areas are called lesions. The skin lesions of KS may look bad, but in many cases, the lesions cause no symptoms. In other cases, the disease causes painful swelling, especially in the legs, groin area, or skin around the eyes. KS can cause serious problems (or even become life threatening) when the lesions are in the lungs, liver, or digestive tract. KS in the digestive tract, for example, can cause bleeding, while tumors in the lungs may cause difficulty breathing.